Rho1 Arae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ara |
| Right ascension | 16h 56m 08.8420s[1] |
| Declination | −50° 40′ 29.243″[1] |
| Apparent magnitude (V) | 6.275[2] |
| Characteristics | |
| Spectral type | B3 Vnpe |
| U−B color index | −0.691[2] |
| B−V color index | +0.008[2] |
| Astrometry | |
| Radial velocity (Rv) | +19[3] km/s |
| Proper motion (μ) | RA: −9.403[1] mas/yr Dec.: −9.592[1] mas/yr |
| Parallax (π) | 3.3089±0.0441 mas [1] |
| Distance | 990 ± 10 ly (302 ± 4 pc) |
| Absolute magnitude (MV) | −0.16[4] |
| Orbit [5] | |
| Period (P) | 236.50±0.18 d |
| Inclination (i) | 60±7° |
| Periastron epoch (T) | HJD 2458672.10±0.72 |
| Semi-amplitude (K1) (primary) | 4.33±0.05 km/s |
| Semi-amplitude (K2) (secondary) | 52.83±1.49 km/s |
| Details | |
| ρ1 Ara A | |
| Mass | 6.5±1.3[5] M☉ |
| Radius | 4.21±0.20[6] R☉ |
| Luminosity | 1,418[7] L☉ |
| Surface gravity (log g) | 3.75[8] cgs |
| Temperature | 19,800[8] K |
| Rotational velocity (v sin i) | 370±10[9] km/s |
| Age | 18.4±1.5[10] Myr |
| ρ1 Ara B | |
| Mass | 0.53±0.11[5] M☉ |
| Radius | 0.27±0.04[6] R☉ |
| Luminosity | 204[6] L☉ |
| Temperature | 42,000[6] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
Rho1 Arae is the Bayer designation for a star in the southern constellation of Ara. Unusually for a star with a Bayer designation, it was not catalogued by Bayer in his Uranometria . It was instead first catalogued by Nicolas Lacaille, in his Coelum Australe Stelliferum published in 1763. This star gained the Bayer designation of Rho1 Arae in Bode's Uranographia , published in 1801. Rho1 Arae is one of the dimmest stars with a Bayer designation, having an apparent visual magnitude of just +6.275[2] According to the Bortle Dark-Sky Scale, this means the star is just barely visible to the naked eye in dark rural skies. Based upon parallax measurements, it is about 990 light-years (302 parsecs) distant from the Sun.[1]
Hipparcos data revealed that Rho1 Arae is a variable star. It was given its variable star designation, V846 Arae, in 1999.[13] This is a spectroscopic binary system, which means that the presence of an orbiting companion is indicated by shifts in the spectrum. The primary star is a Be star, while the secondary star is a subdwarf O star; they orbit each other with a period of about 236.50 days.[5] The combined spectrum of this system matches a stellar classification of B3 Vnpe, which may indicate the primary is a B-type main-sequence star. The 'e' suffix indicates the presence of emission lines from the primary Be star. For Rho1 Arae, the emission lines are prominent and variable.[9] The primary star is spinning rapidly with a projected rotational velocity of 370±10 km/s, which makes it difficult to obtain reliable orbital elements.[9]
Rho1 Arae has a peculiar velocity of 27.4±4.9 km/s relative to its neighbors,[10] making it a runaway star system. A scenario that it was ejected from the Scorpius–Centaurus OB association as a result of a past supernova explosion seems unlikely because of its binarity.[9]
References
[edit ]- ^ a b c d e f Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211 . Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940 . S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d Kozok, J. R. (September 1985), "Photometric observations of emission B-stars in the southern Milky Way", Astronomy and Astrophysics Supplement Series, 61: 387–405, Bibcode:1985A&AS...61..387K.
- ^ Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick (eds.), Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, vol. 30, University of Toronto: International Astronomical Union, p. 57, Bibcode:1967IAUS...30...57E.
- ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971 , Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c d Wang, Luqian; Gies, Douglas R.; Peters, Geraldine J.; Han, Zhanwen (April 2023), "The Orbital and Physical Properties of Five Southern Be+sdO Binary Systems", The Astronomical Journal, 165 (5): 203, arXiv:2303.12616 , Bibcode:2023AJ....165..203W, doi:10.3847/1538-3881/acc6ca , ISSN 1538-3881.
- ^ a b c d Wang, Luqian; Gies, Douglas R.; Peters, Geraldine J.; Götberg, Ylva; Chojnowski, S. Drew; Lester, Kathryn V.; Howell, Steve B. (2021), "The Detection and Characterization of Be+sdO Binaries from HST/STIS FUV Spectroscopy", The Astronomical Journal, 161 (5): 248, arXiv:2103.13642 , Bibcode:2021AJ....161..248W, doi:10.3847/1538-3881/abf144 .
- ^ Hohle, M. M.; Neuhäuser, R.; Schutz, B. F. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten, 331 (4): 349, arXiv:1003.2335 , Bibcode:2010AN....331..349H, doi:10.1002/asna.200911355, S2CID 111387483.
- ^ a b Soubiran, C.; Le Campion, J.-F.; Cayrel de Strobel, G.; Caillo, A. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, arXiv:1004.1069 , Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247, S2CID 118362423.
- ^ a b c d Jilinski, E.; et al. (September 2010), "A Dynamical Study of Suspected Runaway Stars as Traces of Past Supernova Explosions in the Region of the Scorpius–Centaurus OB Association", The Astrophysical Journal, 721 (1): 469–477, Bibcode:2010ApJ...721..469J, doi:10.1088/0004-637X/721/1/469 .
- ^ a b Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society , 410 (1): 190–200, arXiv:1007.4883 , Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x , S2CID 118629873.
- ^ "rho01 Ara", SIMBAD , Centre de données astronomiques de Strasbourg , retrieved 2012年08月01日.
- ^ MAST: Barbara A. Mikulski Archive for Space Telescopes, Space Telescope Science Institute, retrieved 8 December 2021.
- ^ Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V.; Frolov, M. S.; Antipin, S. V.; Kireeva, N. N.; Pastukhova, E. N. (January 1999), "The 74th Special Name-list of Variable Stars", Information Bulletin on Variable Stars, 4659: 1, Bibcode:1999IBVS.4659....1K.